Depends. On my SV 1000 1/8 of a turn on the front compression made a noticeable difference. On my 600 I couldn't detect any difference on the rear rebound no matter how much I wound the rebound adjuster.Originally Posted by imdying
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Depends. On my SV 1000 1/8 of a turn on the front compression made a noticeable difference. On my 600 I couldn't detect any difference on the rear rebound no matter how much I wound the rebound adjuster.
Forum whore
You cannot relate it that way in percentage terms. The reality is that as the bypass needles get further withdrawn ( softer ) they are getting so far out of the bypass orifice that the latter stages have much less percentage impact on damping force change. As you get further and further in a incremental change in position ( say 1/8th of a turn ) has a much much greater percentage change than if it is a long way out.
It is not linear.
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Of course what also needs to be taken into account is that first world countries such as North America and the main European economies will have a much higher percentage of relatively smooth roads. Roads that dont challenge the suspension like our ''goat tracks'' here in the shaky isles. So internet posted settings and overseas mag settings should not be treated as gospel.
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With GSXR600 / 750 we have now modified in excess of 30 sets of forks because they severely lack high speed rebound control. The effect of that is that when you have gone deep into a corner and have used all the travel up the bike tries to ''stand up'' all too readily as you release the brakes. That causes a little bit of instability and makes the bike understeer off especially the tightest turns.
People try and ''tune'' this out by moving the rebound clickers in further and further and it kind of fudges it but then introduces another problem. That rebound adjuster moves a needle in the bottom of the cartridge rod which affects flow not only in extension ( rebound ) but also in compression. By having that adjuster in so far it gives a little more high speed rebound ( but actually not enough ) but also gives too much low speed rebound and too much low speed compression.
So at the top of the stroke as its extending ( accelerating off corners ) the forks are very lethargic in action and that harms their responsiveness to suface irregularities both on the upramps of same and downramps. that affects the grip your tyre has with the road surface! if the low speed rebound is too lethargic it is ''slowing down'' / impeding the ability of the fork springs to put as much pressure as possible on the tyre. Loss of grip.
Moreover, if the adjusters end up in a crazy place the damping can cavitate. The working range of these adjusters that gives you good response but doesnt also overdamp at low shaft speeds is actually a lot narrower than people think. They are not a magic fix all and dont compensate for any internal valving deficiencies, that account for 90% or more of mass flow.
If you are going to end up doing track days on this bike it is essential to get those forks sorted and to also disarm 80% of the hydraulic bottom outs in them, this being a great way to crash if not done, or at least increase the chances markedly.
With respect to the rear the high speed compression adjuster can often be counterintuitive, especially if you are using it as a tuning tool when the fitted main spring rate is correct ( not too stiff as it is now ) Sometimes a very soft preload setting on that high speed adjuster can make the bike feel too stiff over bumps. It acts like a preloadable dump valve when you ride over an abrupt bump. If it dumps too much oil too quickly it allows the chassis to ''blow through its stroke too readily and too quickly. That causes it to get deeper into the rising rate curve of the linkage, the deeper in it gets the faster and further the shock shaft moves for any given distance of wheel movement. The faster you move that shock shaft the greater the damping force created. Relate that to a humble door closing damper........move the door only slowly and resistance is only light, try and move it faster and it almost locks up in your hands.
Stiffer can often be softer!!!
On models with ridiculously progressive links ( Ducati 848 thru 1198, 09 Yamaha R1 and Triumph 675 series ) the trick with suspension is to keep it high in its stroke to do all its best work and to keep it ''way from the link'' as much as possible.
Although its oversimplistic think of it all in these terms: springs are roughly about position, damping is about controlling rate of change of position.
E-mail me your e-mail address and Ill transmit to you a complimentary set up tips manual. I can also forward you a price to upspec those forks, its actually very affordable. Talk to Dipshit and Pussy about it also, they have had it done.
Weekend cruiser
I am fortunate that I never carry a pillion on my R6 so I can run a light 7.0 N/mm spring which is about as soft as I can get away with. Wonderfully complient on NZ roads, but would be too light to handle a pilllion.
(I don't do track days and I don't go fast on roads I don't know, so bottoming out has not been a problem for me.)
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